Generally, semiconductor devices may be formed on a semiconductor wafer using a variety of processing methodologies. These processing steps may include (among others) such processes as etching processes, deposition processes, implantation processes, planarization processes, plating processes, annealing processes, and/or masking processes. These processes, utilized in combination, may be used to form semiconductor devices such as transistors, resistors, capacitors and other devices and may also be used form interconnections between the devices in order to form functional circuitry within a semiconductor die.
Multiple semiconductor dies may be formed on a single semiconductor wafer. As more semiconductor dies are manufactured for sale, more semiconductor wafers may be processed using similar if not identical processes. By using similar or identical processes, the same semiconductor devices may be formed on multiple semiconductor wafers. Once manufactured, the multiple dies may be singulated from the semiconductor wafers, and similar semiconductor dies may be grouped together and packaged together for sale and eventual shipment to customers.
However, as semiconductor devices and their respective semiconductor dies are scaled down to smaller and smaller sizes, variations in processes that were initially perceived as being similar or identical can actually cause process variations between different semiconductor wafers. Further, as the scaling continues to even smaller and smaller sizes, and the tolerances of the processing parameters becomes tighter and tighter, these process variations may not only begin to affect the processing, but may also actually cause individual semiconductor wafers to vary far enough that undesired deviations from the semiconductor die's desired functionality may occur.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale.